That 'presence' is in my experience, present throughout much of Wales, more notably the Hafod area. The Hafod and the Rheidol/Mynach areas around Devil's Bridge literally 'buzz' with something, both unnerving and awe-inspiring. Strata Florida has seen me right off, couldn't camp there just on account of the semi-veiled malignancy the place emitted. Funny you mention Blodwedd, Wales is most definately a female energy, like no other I've felt. If the Morrigan lives anywhere, you'll find her there, for sure. Whispers in the trees, eyes in the rocks, and the truth of life in running rivers.
*brrrrrrzzzurrr*